OEM belt sample approval should verify more than appearance before a buyer commits to bulk production. This guide explains how procurement and quality teams can lock drawings and revisions, inspect dimensions and construction, define relevant performance tests, distinguish development samples from production-representative samples, document deviations, evaluate supplier process control, and connect approval records to the final purchase order. It also provides a practical checklist for reducing specification, quality, branding, and repeat-order risks when sourcing conveyor belts and transmission belts from an OEM supplier.